Recycle-ready retortable laminated polyester-based films

ABSTRACT

In one aspect, a pouch includes a first panel, a second panel, and a bottom gusset, wherein the first panel, second panel, and bottom gusset are formed of a polyester-based film structure and wherein the bending stiffness of the bottom gusset panel is less than or equal to 0.05 N mm. Each of the polyester-based film structures may be formed of a polyester-based polymeric composition comprising polybutylene terephthalate (PBT), polyethylene terephthalate (PET), or a blend from 0-100% by weight of PBT in PET. It is contemplated that each polyester-based film structure may comprise two or more film plies laminated to each other.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.17/339,426 filed Jun. 4, 2021, which in turn claims the priority benefitof U.S. provisional application No. 63/041,357 filed Jun. 19, 2020, andU.S. provisional application No. 63/127,925 filed Dec. 18, 2020. Each ofthe aforementioned applications is incorporated herein by reference inits entirety.

BACKGROUND

The present disclosure relates to packaging articles and moreparticularly to a recycle-ready, high-barrier, laminated polyester-basedgusseted pouch. The polyester-based gusseted pouches are formed ofopposing panels having a film structure comprising two or more polyesterfilm ply layers laminated together and a bottom gusset panel. In thepreferred embodiments, the pouch is adapted for use as a retortablepouch; however, it is also contemplated that the pouches herein canadvantageously be used as a barrier pouch for non-retort applications.The film structure has one or more polyester-based layers comprisingpolybutylene terephthalate (PBT), polyethylene terephthalate (PET), or ablend from 0-100% by weight of PBT in PET. At least one polyester-basedlayer is a high-barrier, ceramic-coated layer, where the ceramic coatingcomprises fully or partially oxidized aluminum, fully or partiallyoxidized silicon, or a blend thereof.

The pouches of this disclosure may be used for retort applications orany other application where a stand-up type pouch is desirable toprotect consumable products from spoiling or prematurely degrading invarious environments throughout the distribution and point of salechannels. Such packaging articles may be used for sterile packaging ofhuman and pet food items, liquids, chemicals, health and medicalproducts, beauty products, and other consumable product that needs to beprotected from oxygen and moisture after retort process. In particularlypreferred embodiments, the film structures may be used in themanufacture of a retortable pouch for the sterile packaging of food anddrink handled by aseptic processing. Conventional film structures forretortable pouches commonly use a foil or nylon layer, which renders thepackaging product unsuitable for recycling. In contrast, the filmstructures of the present packaging construction are substantially freeof non-polyester-based polymers.

Flexible PET packaging films are more susceptible to damage, such assuffering punctures, during transport. While all-polyester packagingfilms have been developed that are suitable for non-gusseted foodpackaging bags, such as pillow shaped packaging bags, the development ofan all-polyester gusseted pouch has been met with difficulty at numerousstages. For examples, difficulties arise in forming a hermetic seal,pushing a sealable layer of polyester sealant to flow and cover thespace between gusset panels and side seal area (in some embodiments,referred to as the triple point), and filling packaging, due to thethickness and stiffness of the material, as well as maintainingintegrity of material through retort processes. For example, U.S. Pat.No. 6,543,208 discloses a pillow shaped polyester film food packagingbag. The packaging bags of U.S. Pat. No. 6,543,208 are formed of atubular bag having a longitudinal fin seal and transverse seals at eachend. The films disclosed U.S. Pat. No. 6,543,208 have a seal initiationtemperature of approximately 122 degrees C. (see FIG. 1 of U.S. Pat. No.6,543,208). While such films are suitable for pillow shaped polyesterfilm food packaging bags having a longitudinal fin seal and transverseend seals, such films are not suitable for gusseted pouches.

The present development overcomes these limitations by providing aretortable polyester film having a low bending stiffness in the gussetedportion, a low coefficient of friction, and low seal initiationtemperatures. This results in a film suitable for forming hermetic,recycle-ready gusseted pouches capable of running on high-speedpackaging lines. It will be recognized that the present development isnot limited to retort packaging applications and is suitable fornon-retort packaging applications.

The present disclosure provides an improved packaging article and methodthat overcomes the above-referenced problems and others.

SUMMARY

In one aspect, a pouch includes a first panel having an upper end, alower end, an interior surface facing an interior of the pouch, and anexterior surface at an exterior of the pouch. A second panel is oppositethe first panel, the second panel having an upper end, a lower end, aninterior surface facing the interior of the pouch, and an exteriorsurface at the exterior of the pouch, the first and second panelscooperating to define at least a portion of a cavity, the upper ends ofthe first and second panels spaced apart from the lower ends of thefirst and second panels in an axial direction. A bottom gusset panelextends between the lower end of the first panel and the lower end ofthe second panel and defines a lower end of the cavity. The bottomgusset panel has an interior surface facing the interior of the pouchand an exterior surface at the exterior of the pouch, wherein the bottomgusset panel is folded along a fold line extending parallel to the lowerends of the first panel and the second panel when the pouch is empty,the fold line spaced apart from the lower ends of the first and secondpanels toward the upper ends of the first and second panels, wherein afirst axial extent of the pouch between the lower ends of the first andsecond panels and the fold line defines a gusset region, and wherein asecond axial extent of the pouch between the fold line and the upperends of the first and second panels defines a non-gusset region. Thebottom gusset panel is configured to permit the lower ends of the firstand second panels to be spaced apart from each other to expand a lowerend of the pouch when the cavity is at least partially filled. A firstside seal region extends in the axial direction, wherein the first andsecond panels are sealed to each other along a first peripheral edge ofthe non-gusset region and wherein the first and second panels are sealedto the bottom gusset panel along a first peripheral edge of the gussetregion. A second side seal region extends in the axial direction andtransversely opposite the first side seal region, wherein the first andsecond panels are sealed to each other along a second peripheral edge ofthe non-gusset region and wherein the first and second panels are sealedto the bottom gusset panel along a second peripheral edge of the gussetregion. A first bottom seal region wherein the first panel is sealed tothe bottom gusset panel along a bottom peripheral edge of the gussetregion. A second bottom seal region wherein the second panel is sealedto the bottom gusset panel along the bottom peripheral edge of thegusset region. A seal region at an upper end of the pouch is configuredto close the cavity when sealed. The first panel, second panel, andbottom gusset panel are formed of a polyester-based film structure. Thebending stiffness of the bottom gusset panel is less than or equal to0.05 N mm.

In a more limited aspect, one or more of the first panel, second panel,and bottom gusset panel are formed of a polyester-based film comprisinga first ply which includes a first layer formed of a firstpolyester-based polymeric composition, wherein the first polyester-basedpolymeric composition comprises polybutylene terephthalate, polyethyleneterephthalate, or a blend thereof. The first layer has a first surfaceand a second surface opposite the first surface. A second ply includes asecond layer, the second layer having a first surface and a secondsurface opposite the first surface, and wherein the second layer is asealable polyester layer. A third layer is formed of a secondpolyester-based polymeric composition, wherein the secondpolyester-based polymeric composition comprises polybutyleneterephthalate, polyethylene terephthalate, or a blend thereof. Anadhesive layer is interposed between the first ply and the second ply,the adhesive layer laminating the first ply to the second ply, whereinthe first surface of the third layer faces the second surface of thefirst layer.

In a more limited aspect, each of the first ply and the second ply havea thickness in the range of about 9 microns to 100 microns.

In a more limited aspect, the sealable polyester layer has a thicknessin the range of about 2 microns to 25 microns.

In a more limited aspect, the polyester-based film further includes aprinted layer disposed intermediate the first layer and the adhesivelayer.

In a more limited aspect, the first ply further includes a fourth layerformed of a ceramic coating, the fourth layer having a first surface anda second surface opposite the first surface, wherein the first surfaceof the fourth layer faces the second surface of the first layer. A fifthlayer is interposed between the second layer and the printed layer.

In a more limited aspect, the second ply further includes a fourth layerformed of a ceramic coating, the fourth layer having a first surface anda second surface opposite the first surface, wherein the first surfaceof the fourth layer faces the adhesive layer. A fifth layer isinterposed between the fourth layer and the third layer.

In a more limited aspect, the polyester-based film structure has a sealinitiation temperature of less than or equal to 120° C.

In yet another more limited aspect, the polyester-based film structurehas a seal initiation temperature of less than or equal to 100° C.

In a more limited aspect, the polyester-based film structure has a heatseal strength in the range of about 10 N/25 mm to about 100 N/25 mm,preferably about 15 N/25 mm to about 100 N/25 mm, and more preferablyabout 20 N/25 mm to about 100 N/25 mm.

In a more limited aspect, the polyester-based film structure has anultrasonic seal strength in the range of about 10 N/25 mm to about 100N/25 mm, preferably about 15 N/25 mm to about 100 N/25 mm, and morepreferably about 20 N/25 mm to about 100 N/25 mm.

In a more limited aspect, the polyester-based film structure has amaximum seal strength in the range of about 10 N/25 mm to about 100 N/25mm, preferably in the range of about 15 N/25 mm to about 32 N/25 mm, andmore preferably about 20 N/25 mm to about 30 N/25 mm.

In a more limited aspect, the polyester-based film structure has aminimum seal strength of greater than or equal to 10 N/25 mm, preferablygreater than or equal to 15 N/25 mm, and more preferably greater than orequal to 20 N/25 mm. In a more limited aspect, the minimum sealtemperature to achieve the minimum seal strength is less than or equalto 115 degrees C., preferably less than or equal to 100 degrees C., morepreferably less than or equal to 90 degrees C.

In a more limited aspect, the minimum seal temperature to achieve a sealstrength of at least 10 N/25 mm is less than or equal to 115 degrees C.,preferably less than or equal to 100 degrees C., more preferably lessthan or equal to 90 degrees C.

In a more limited aspect, the sealable polyester layer has a staticcoefficient of friction in the range of about 0.1 to 0.4 and a kineticcoefficients of friction in the range of about 0.1 to 0.4.

In a more limited aspect, the polyester-based film structure has anoxygen transmission rate of less than or equal to 0.1 cc/100 in²/day (at23 degrees C., 0% relative humidity) and a moisture vapor transmissionrate of less than or equal to 0.1 g/100 in²/day (at 38 degrees C., 90%relative humidity) before undergoing a retort process. In a further morelimited aspect, the polyester-based film structure has an oxygentransmission rate of less than or equal to 0.05 cc/100 in²/day (at 23degrees C., 0% relative humidity) and a moisture vapor transmission rateof less than or equal to 0.05 g/100 in²/day (at 38 degrees C., 90%relative humidity) before undergoing a retort process.

In a more limited aspect, the polyester-based film structure has anoxygen transmission rate of less than or equal to 0.1 cc/100 in²/day (at23 degrees C., 0% relative humidity) and a moisture vapor transmissionrate of less than or equal to 0.1 g/100 in²/day (at 38 degrees C., 90%relative humidity) after undergoing a retort process. In a further morelimited aspect, the polyester-based film structure has an oxygentransmission rate of less than or equal to 0.05 cc/100 in²/day (at 23degrees C., 0% relative humidity) and a moisture vapor transmission rateof less than or equal to 0.05 g/100 in²/day (at 38 degrees C., 90%relative humidity) after undergoing a retort process.

In a more limited aspect, each of the first and second panels are formedof a polyester-based film comprising a first ply which includes a firstlayer formed of a first polyester-based polymeric composition, whereinthe first polyester-based polymeric composition comprises polybutyleneterephthalate, polyethylene terephthalate, or a blend thereof. The firstlayer has a first surface and a second surface opposite the firstsurface. A second ply includes a second layer, the second layer having afirst surface and a second surface opposite the first surface, andwherein the second layer is sealable polyester layer. A third layer isformed of a second polyester-based polymeric composition, wherein thesecond polyester-based polymeric composition comprises polybutyleneterephthalate, polyethylene terephthalate, or a blend thereof. A thirdply includes a fourth layer formed of a third polyester-based polymericcomposition, the fourth layer having a first surface and a secondsurface opposite the first surface. An adhesive layer is interposedbetween the first ply and the third ply, the adhesive layer laminatingthe first ply to the third ply, wherein the first surface of the fourthlayer faces the second surface of the first layer. A second adhesivelayer is interposed between the second ply and the third ply, the secondadhesive layer laminating the second ply to the third ply, wherein thesecond surface of the fourth layer faces the first surface of the thirdlayer.

In a more limited aspect, the third polyester-based polymericcomposition comprises polybutylene terephthalate, polyethyleneterephthalate, or a blend thereof.

In a more limited aspect, the polyester-based film structure furtherincludes a printed layer disposed intermediate the fourth layer and thesecond adhesive layer.

In a more limited aspect, each of the first ply, third ply, and secondply have a thickness in the range of about 9 microns to 100 microns.

In a more limited aspect, the sealable polyester layer has a thicknessin the range of about 2 microns to 25 microns.

In a more limited aspect, a printed layer is disposed intermediate thesecond layer and the adhesive layer.

In a more limited aspect, the first ply further includes a fifth layerformed of a ceramic coating, the fifth layer having a first surface anda second surface opposite the first surface, wherein the first surfaceof the fifth layer faces second surface of the first. A sixth layer isinterposed between the fifth layer and the printed layer.

In a more limited aspect, the second ply further includes a fifth layerformed of a ceramic coating, the fifth layer having a first surface anda second surface opposite the first surface, wherein the first surfaceof the fifth layer faces the second adhesive layer. A sixth layer isinterposed between the fifth layer and the third layer.

In a more limited aspect, the sealable polyester layer has a staticcoefficient of friction in the range of about 0.1 to 0.4 and a kineticcoefficients of friction in the range of about 0.1 to 0.4.

One advantage of the present packaging article is that it does notrequire a foil or nylon layer and therefore can be adapted for thepolyester recycle stream.

Another advantage of the present development is the laminated polyesterfilm ensures high oxygen and water vapor barrier even after retortprocessing, ensuring that product quality and shelf life are notcompromised.

Another advantage of the present development relates to themanufacturing of gusseted pouches formed of a laminated film structurewhich covers and hermetically seals the space formed by panels joinedtogether to form the gusset section of gusseted pouches.

Another advantage of the present development relates to the ability toprovide a recycle-ready, retortable, polyester-based film package withgussets.

Another advantage of the present development relates to ease with whichthe gusseted packaging may be opened for filling and run on high-speedpackaging lines.

Another advantage of the present development resides in its utility inthe packaging of certain products having oily residue, such as pet foodproducts. The presently disclosed packaging article is able to produce agood seal at thermal ultrasonic sealing step(s) of packaging process.

Still further advantages and benefits of the present invention willbecome apparent to those of ordinary skill in the art upon reading andunderstanding the following detailed description of the preferredembodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may take form in various components and arrangements ofcomponents, and in various steps and arrangements of steps. The drawingsare only for purposes of illustrating preferred embodiments and are notto be construed as limiting the invention.

FIG. 1 is a front view of an exemplary gusseted packaging pouch formedof a laminated film structure.

FIG. 2 is a rear view of the packaging pouch shown in FIG. 1 .

FIG. 3 is a side view of the pouch in FIG. 1 illustrating triple pointarea between the gusset portion and the side seal portion.

FIG. 4A is a front view of an exemplary gusseted packaging pouch formedof a laminated film structure.

FIG. 4B is a side cross-sectional view of the triple point area betweenthe gusset panels and the side seal portion of the packaging pouch shownin FIG. 1 .

FIG. 4C is a side cross-sectional view of the triple point area betweenthe gusset panels and the side seal portion of the packaging pouch shownin FIG. 1 with polyester-based sealant covering the trip point area.

FIG. 5 is a side cross-sectional view of a first embodiment of apackaging pouch panel comprising two polyester-based film ply layerslaminated together.

FIG. 6 is a side cross-sectional view of a second embodiment of apackaging pouch panel comprising two polyester-based film ply layerslaminated together.

FIG. 7 is a side cross-sectional view of a third embodiment of apackaging pouch panel comprising three polyester-based film ply layerslaminated together.

FIG. 8 is a side cross-sectional view of a fourth embodiment of apackaging pouch panel comprising three polyester-based film ply layerslaminated together.

FIG. 9 is a side cross-sectional view of a fifth embodiment of apackaging pouch panel comprising three polyester-based film ply layerslaminated together.

FIG. 10 is a side cross-sectional view of a sixth embodiment of apackaging pouch panel comprising three polyester-based film ply layerslaminated together.

FIG. 11 is a side cross-sectional view of a seventh embodiment of apackaging pouch panel comprising four or more polyester-based film plylayers laminated together.

FIG. 12 illustrates an exemplary polyester-based polymer layer having abarrier coating and top coating.

FIG. 13 illustrates an exemplary polyester-based polymer layer.

FIG. 14 illustrates an exemplary sealable polyester-based film having abarrier coating and a top coating.

FIG. 15 illustrates an exemplary sealable polyester-based film.

FIG. 16 is a graph of seal strength as a function of temperaturecomparing a gusseted standup pouches formed of polyester film using apolyester sealant layer having a low seal initiation temperature inaccordance with the present invention (referred to herein as “suitablesealant”) to three commercially available polyester sealant layersconventionally used for polyester pouch constructions, which have beenfound to be unsuitable for use with gusseted pouch constructions(referred to herein as “non-suitable sealants”).

FIG. 17A is an image of an exemplary gusseted pouch constructed withpolyester film having a suitable polyester sealant in accordance withthis disclosure.

FIG. 17B is an enlarged view of the triple point region of the gussetedpouch appearing in FIG. 17A.

FIG. 18A is an image of a gusseted pouch constructed with polyester filmhaving a conventional, unsuitable suitable polyester sealant.

FIG. 18B is an enlarged view of the triple point region of the gussetedpouch appearing in FIG. 18A.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Detailed embodiments of the present development are disclosed herein;however, it is to be understood that the disclosed embodiments aremerely exemplary of the invention, which may be embodied in variousforms. Therefore, specific structural and functional details disclosedherein are not to be interpreted as limiting but merely as a basis forthe claims and as a representative basis for teaching one skilled in theart to variously employ the present inventive concept in virtually anyappropriately detailed structure. Further, the terms and phrases usedherein are not intended to be limiting but rather to provide anunderstandable description of the present development.

The terms “a” or “an,” as used herein, are defined as one or more thanone. The term “another,” as used herein, is defined as at least a secondor more. The terms “including” and/or “having” as used herein, aredefined as comprising (i.e., open transition). The term “coupled” or“operatively coupled,” as used herein, is defined as indirectly ordirectly connected.

As used herein, the term “bending stiffness” refers to a measure of amaterial's resistance against bending deformation. In some embodiments,the bending stiffness of a film ply may be represented by the followingformula:

S=EI/b

where “S” represents bending stiffness, “E” represents the film'selastic modulus, “I” represents the moment of inertia of a crosssection, and “b” represents the width of the beam. Considering that themodulus and thickness of the adhesive is negligible compared to themodulus and thickness of the polyester film, polyester-based filmstructure can be considered as a monolayer. So, using the above equationand considering the moment of inertia (I) of a rectangular cross-sectionis represented by the formula

$\left. {I = {b\frac{t^{3}}{12}}} \right),$

where b” is as defined above and “t” represents the thickness of thefilm, the bending stiffness S can be calculated as a function ofthickness of the film:

S=E*t ³/12

Referring now to the drawings, FIGS. 1-4 illustrate an exemplarypolyester-based gusseted pouch 1000, formed of one or more of theexemplary polyester-based packaging film structures and manufactured inaccordance with exemplary embodiments of the present invention.

In certain embodiments, the pouch 1000 is formed of a front portion1010, a back portion 1011, and a gusset portion 1050 having a fold 1015.FIGS. 4A-C illustrate the space formed by the sides of the gussetportion 1050 and the side seal area 1030, which is referred to as thetriple point area 1020.

FIGS. 5-7 illustrate exemplary polyester based packaging film structuresfor forming the polyester-based gusseted packaging 1000 in accordancewith exemplary embodiments of the present invention. The packaging filmstructures illustrated have low seal initiation temperature for formingthe packaging 1000, and maintain low oxygen and water vapor transmissionrates after retort processing. In certain embodiments, the laminatedstructure is flexible with low stiffness such that the gusset portion isable to be opened with less than or equal to 40 mBar of pressure in thepackage filling process. In certain preferred embodiments, the bendingstiffness of the gusset film panel 1050 is less than or equal to 0.05 Nmm. The low bending stiffness of the bottom panel 1050 also aids in theformation of a hermetic seal at the triple point area 1020.

The film used for the bottom gusset panel 1050 will preferably have atwo or three ply structure, e.g., as shown in FIGS. 5-7 , although filmswith other numbers of plies, e.g., 4, 5, 6, 7, 8, or more plies, so longas the bending stiffness of the film panel 1050 is less than or equal to0.05 N mm. It has been found that a bottom panel with low bendingstiffness contributes to the ease of gusset opening as well as achievinga hermetic seal at the triple point area. Thus, the front and rear pouchpanels 1010 and 1011 may have any desired bending stiffness, so long asthe bending stiffness of the gusset panel is less than or equal to 0.05N mm. In reducing the present invention to practice, it has been foundthat increasing the bending stiffness of the film used for the gussetportion to 0.07 N mm while using the suitable sealant as discussedherein resulted in a pouch that was not hermetic and leaking at thetriple point area 1020. In addition, increasing the bending stiffness ofthe film used for the gusset portion to 0.07 N mm resulted in a gussetopening pressure that ranged between 20 to 80 mBar, and therefore couldnot consistently achieve the desired opening pressure of less than orequal to 40 mbar.

Referring now to FIG. 5 , there appears a first embodiment packagingfilm structure 100, which includes a first ply 110 r laminated to asecond ply 120. In certain embodiments, the first ply 110 r is an outerply and the second ply 120 is an inner ply. An adhesive layer 40 isinterposed between the first ply 110 r and the second ply 120 to form alaminated structure. The adhesive layer 40 may be formed of any suitableadhesive including single component adhesives, two component adhesives,solvent-based adhesives, solventless adhesives, water-based adhesives,acrylic adhesives, electron beam lamination adhesives, and UV laminationadhesives, as would be understood by persons skilled in the art.

The first ply 110 r is composed of a high-barrier polyester-based layerformed on an outer portion of the recycle-ready packaging film structure100. The ply 110 r includes a polyester-based film 10. Thepolyester-based film 10 is formed of a polyester-based polymericcomposition. In certain embodiments, the polyester-based polymercomposition comprises polybutylene terephthalate (PBT), polyethyleneterephthalate (PET), or a blend of PBT and PET, wherein the ratio of PBTand PET is adjustable from 0-100% by weight of PBT in PET, depending onthe packaging application.

In certain embodiments, the first ply 110 r further includes a ceramiccoating layer 20, formed on a first, inward facing surface of thepolyester-based film 10. In certain embodiments, a second outward facingsurface of the polyester-based film 10, opposite the first surface, isuncoated, and forms the outermost portion of the film structure 100. Incertain embodiments, the ceramic coating 20 is formed of partially orfully oxidized aluminum or silicon or a blend of both. In certainembodiments, the ceramic coating 20 is formed of partially or fullyoxidized silicon (SiO_(x), SiO₂), partially or fully oxidized aluminum(AlO_(x), Al₂O₃), or a mixture thereof. An additional top polymercoating layer 25 suitable for closing any cracks created during theretort process is disposed on the ceramic coating layer 20. In certainembodiments, the oxygen transmission rate (OTR) and water vapor barrier(moisture vapor transmission rate (MVTR)) of the ply 110 r is less thanor equal to 0.1 cc/100 in²/day (at 23 degrees C., 0% relative humidity)(and preferably 0.05 cc/100 in²/day (at 23 degrees C., 0% relativehumidity)) and 0.1 g/100 in²/day (at 38 degrees C., 90% relativehumidity) (and preferably 0.05 g/100 in²/day (at 38 degrees C., 90%relative humidity)), respectively, even after retort processing,ensuring that product quality and shelf life are not compromised.

A printing ink layer 30 r is disposed on the polyester-based film 10. Incertain embodiments, where the polyester-based film 10 is a barrierpolyester-based film, such as illustrated in FIG. 12 , the printing inklayer 30 r is disposed on the coating layer 25 on the inward facingsurface thereof, opposite the surface facing the ceramic coating layer20. The printing ink layer 30 r provides printed indicia intended toappear on a packaging article formed from the film structure 100.Because the printing ink layer 30 r is applied to the inward facingsurface of the polyester-based film 10, the printed material is effectedin a reverse printed format. The printing ink layer 30 r can be appliedto the inward surface of the coating layer 25 via any conventionalprinting method as would be understood by persons skilled in the art,including without limitation, using a rotogravure printing apparatus orflexographic printing apparatus.

The second ply 120 includes a sealable polyester-based film 50. Incertain embodiments, the sealable polyester-based film 50 is formed of apolyester-based polymer 12 and a sealable polyester layer 55, such as isdescribed below by way of reference to FIG. 15 . In certain embodiments,the sealable polyester-based film 50 includes a barrier coating 20 and atop coating 25, such as is described below by way of reference to FIG.14 . In certain embodiments, the sealable polyester-based film 50comprises a polyester-based layer 12 and a thin, amorphous, sealablepolyester layer 55. The sealable polyester-based film 50 defines asealant layer and may comprise any polyester-based polymer suitable forproviding a hermetic seal in a finished packaging article, andpreferably has a low seal initiation temperature/melting point. Incertain preferred embodiments, the sealable polyester layer 55 is anamorphous layer having a thickness between 2 to 25 microns. The film 50can be clear polyester sealable film. Alternatively, the film 50 can bewhite (e.g., via the additional of a pigment such as titanium dioxide)to add stiffness to the structure and improve the stain resistanceproperties after the retort process. In certain embodiments, the secondply 120 has static and kinetic coefficients of friction in the range offrom about 0.1 to 0.4. In certain embodiments, the seal initiationtemperature is lower than 120° C. at 40 psi, 0.5 second dwell time. Incertain embodiments, the seal initiation temperature is lower than 100°C. at 40 psi, 0.5 second dwell time. In certain embodiments, the ply 120is selected of a material which provides a seal strength of betweenabout 10 N/25 mm to about 100 N/25 mm, preferably about 15 N/25 mm toabout 100 N/25 mm, and more preferably about 20 N/25 mm to about 100N/25 mm, in order for a packaging article to pass the retort process. Incertain embodiments, the polyester-based film structure has a maximumseal strength in the range of about 10 N/25 mm to about 100 N/25 mm,preferably in the range of about 15 N/25 mm to about 32 N/25 mm, andmore preferably about 20 N/25 mm to about 30 N/25 mm. In certainembodiments, the polyester-based film structure has a minimum sealstrength of greater than or equal to 10 N/25 mm, preferably greater thanor equal to 15 N/25 mm, and more preferably greater than or equal to 20N/25 mm. In certain embodiments, the minimum seal temperature to achievethe minimum seal strength is less than or equal to 115 degrees C.,preferably less than or equal to 100 degrees C., more preferably lessthan or equal to 90 degrees C. In certain embodiments, the minimum sealtemperature to achieve a seal strength of at least 10 N/25 mm is lessthan or equal to 115 degrees C., preferably less than or equal to 100degrees C., more preferably less than or equal to 90 degrees C.

In certain embodiments, the first ply 110 has a thickness of 9 micronsto 100 microns. In certain embodiments, the second ply 120 has athickness of 9 microns to 100 microns. In certain preferred embodiments,the total bending stiffness of the laminated film structure of thegusseted portion of the polyester pouch is below or equal to 0.05 N mmto allow for ease of gusset opening, for example, such that the gussetportions are able to be opened with less than or equal to 40 mBar ofpressure in the package filling process.

Referring now to FIG. 6 , there appears a second embodiment packagingfilm structure 200, comprising a first ply 110 and a second ply 120 f,which are laminated together. The first ply 110 is an outer ply and thesecond ply 120 f is an inner ply. An adhesive layer 40 is interposedbetween the first ply 110 and the second ply 120 f to form a laminatedstructure. The adhesive layer 40 may be formed of an adhesive materialas described above by way of reference to FIG. 5 .

The first ply 110 is formed on an outer portion of the packaging filmstructure 200. The ply 110 includes polyester-based film 10, which maybe formed of PBT, PET, or a blend of 0-100% by weight of PBT in PET, asdescribed above by way of reference to FIG. 5 .

In certain embodiments, the first ply 110 further includes a ceramiccoating 20 formed on a first surface of the polyester-based film 10. Theceramic coating 20 may be formed of a material as described above by wayof reference to FIG. 5 . In certain preferred embodiments, the ceramiccoating 20 is formed of partially or fully oxidized silicon (SiO_(x),SiO₂), partially or fully oxidized aluminum (AlO_(x), Al₂O₃), or amixture thereof. An additional polymer coating layer 25 suitable forclosing any cracks created during the retort process is disposed on theceramic coating layer 20.

The second ply 120 f includes a sealable polyester-based film 50. Incertain embodiments, the sealable polyester-based film 50 is formed of apolyester-based polymer 12 and a sealable polyester layer 55, such as isdescribed below by way of reference to FIG. 15 . In certain embodiments,the sealable polyester film 50 includes a barrier coating 20 and a topcoating 25, such as is described below by way of reference to FIG. 14 .In certain embodiments, the sealable polyester-based film 50 comprises apolyester-based layer 12 and a thin, amorphous, sealable polyester layer55. The sealable polyester-based film 50 defines a sealant layer and maycomprise any polyester-based polymer suitable for providing a hermeticseal in a finished packaging article, and preferably has a low sealinitiation temperature/melting point. In certain preferred embodiments,the sealable polyester layer 55 is an amorphous layer having a thicknessbetween 2 to 25 microns. The film 50 can be clear polyester sealablefilm. Alternatively, the film 50 can be white (e.g., via the additionalof a pigment such as titanium dioxide) to add stiffness to the structureand improve the stain resistance properties after the retort process. Incertain embodiments, the second ply 120 f has static and kineticcoefficients of friction in the range of from about 0.1 to 0.4. Incertain embodiments, the seal initiation temperature is lower than 120°C. at 40 psi, 0.5 second dwell time. In still further embodiments, theseal initiation temperature is lower than 100° C. at 40 psi, 0.5 seconddwell time. In certain embodiments, the ply 120 f is selected of amaterial which provides a seal strength of between about 10 N/25 mm toabout 100 N/25 mm, preferably about 15 N/25 mm to about 100 N/25 mm, andmore preferably about 20 N/25 mm to about 100 N/25 mm, in order for apackaging article to pass the retort process. In certain embodiments,the polyester-based film structure has a maximum seal strength in therange of about 10 N/25 mm to about 100 N/25 mm, preferably in the rangeof about 15 N/25 mm to about 32 N/25 mm, and more preferably about 20N/25 mm to about 30 N/25 mm. In certain embodiments, the polyester-basedfilm structure has a minimum seal strength of greater than or equal to10 N/25 mm, preferably greater than or equal to 15 N/25 mm, and morepreferably greater than or equal to 20 N/25 mm. In certain embodiments,the minimum seal temperature to achieve the minimum seal strength isless than or equal to 115 degrees C., preferably less than or equal to100 degrees C., more preferably less than or equal to 90 degrees C. Incertain embodiments, the minimum seal temperature to achieve a sealstrength of at least 10 N/25 mm is less than or equal to 115 degrees C.,preferably less than or equal to 100 degrees C., more preferably lessthan or equal to 90 degrees C.

A printing ink layer 30 f is disposed on an outward facing surface ofthe sealable polyester-based film 50. The printing ink layer 30 fprovides printed indicia intended to appear on a packaging articleformed from the film structure 200. Because the printing ink layer 30 fis applied to the outward facing surface of the sealable polyester-basedfilm 50, the printed material is effected in a front printed format. Theprinting ink layer 30 f can be applied to the outward facing surface ofthe polyester-based film via any conventional printing method as wouldbe understood by persons skilled in the art, including withoutlimitation, using a rotogravure printing apparatus or flexographicprinting apparatus.

In certain embodiments, the first ply 110 has a thickness of 9 micronsto 100 microns. In certain embodiments, the second ply 120 f has athickness of 9 microns to 100 microns. In certain preferred embodiments,the bending stiffness of the laminated film structure of the gussetedportion of the pouch is below or equal to 0.05 N mm to allow for ease ofgusset opening, for example, such that the gusset portions are able tobe opened with less than or equal to 40 mBar of pressure in the packagefilling process. The low bending stiffness also aids in the formation ofa hermetic seal.

Referring now to FIG. 7 , there appears a third embodiment packagingfilm structure 300, comprising a first ply 110 r, a third ply 220, and asecond ply, 120, which are laminated together. The first ply 110 r is anouter ply, the second ply 120 is an inner ply, and the third ply 220 isan intermediate ply interposed between the first and second ply layers.A first adhesive layer 40 a is interposed between the first ply 110 rand the third ply 220 and a second adhesive layer 40 b is interposedbetween the third ply 220 and the second ply 120, to form a laminatedstructure. The adhesive layers 40 a and 40 b may be formed of anadhesive material as described above by way of reference to FIG. 5 .

The first ply 110 r is formed on an outer portion of the packaging filmstructure 300. The ply 110 r includes polyester-based film 10, which maybe formed of PBT, PET, or a blend of 0-100% by weight of PBT in PET, asdescribed above by way of reference to FIG. 5 .

In certain embodiments, the first ply 110 r further includes a ceramiccoating 20 formed on a first surface of the polyester-based film 10. Theceramic coating 20 may be formed of a material as described above by wayof reference to FIG. 5 . In certain preferred embodiments, the ceramiccoating 20 is formed of partially or fully oxidized silicon (SiO_(x),SiO₂), partially or fully oxidized aluminum (AlO_(x), Al₂O₃), or amixture thereof. An additional polymer coating layer 25 suitable forclosing any cracks created during the retort process is disposed on theceramic coating layer 20.

A printing ink layer 30 r is disposed on the inward facing surface ofpolyester-based film 10. In certain embodiments where thepolyester-based film 10 is a barrier polyester-based film, the printingink layer 30 r is disposed on the coating layer 25 on the surfaceopposite the surface facing the ceramic coating layer 20. The printingink layer 30 r provides printed indicia intended to appear on apackaging article formed from the film structure 300. Because theprinting ink layer 30 r is applied to the inward facing surface of thepolyester-based film 10, the printed material is effected in a reverseprinted format. The printing ink layer 30 r can be applied to the inwardsurface of the coating layer 25 via any conventional printing method aswould be understood by persons skilled in the art, including withoutlimitation, using a rotogravure printing apparatus or flexographicprinting apparatus.

The second ply 120 includes a sealable polyester-based film 50. Incertain embodiments, the sealable polyester-based film 50 is formed of apolyester polymer 12 and a sealable polyester layer 55, such as isdescribed below by way of reference to FIG. 15 .

In certain embodiments, the sealable polyester film 50 includes abarrier coating 20 and a top coating 25, such as is described below byway of reference to FIG. 14 . In certain embodiments, the sealablepolyester-based film 50 comprises a polyester-based layer 12 and a thin,amorphous, sealable polyester layer 55. The sealable polyester-basedfilm 50 defines a sealant layer and may comprise any polyester-basedpolymer suitable for providing a hermetic seal in a finished packagingarticle, and preferably has a low seal initiation temperature/meltingpoint. In certain preferred embodiments, the sealable polyester layer 55is an amorphous layer having a thickness between 2 to 25 microns. Thefilm 50 can be clear polyester sealable film. Alternatively, the film 50can be white (e.g., via the additional of a pigment such as titaniumdioxide) to add stiffness to the structure and improve the stainresistance properties after the retort process. In certain embodiments,the second ply 120 has static and kinetic coefficients of friction inthe range of from about 0.1 to 0.4. In certain embodiments, the sealinitiation temperature is lower than 120° C. at 40 psi, 0.5 second dwelltime. In certain embodiments, the seal initiation temperature is lowerthan 100° C. at 40 psi, 0.5 second dwell time. In certain embodiments,the ply 120 is selected of a material which provides a seal strength ofbetween about 10 N/25 mm to about 100 N/25 mm, preferably about 15 N/25mm to about 100 N/25 mm, and more preferably about 20 N/25 mm to about100 N/25 mm, in order for a packaging article to pass the retortprocess. In certain embodiments, the polyester-based film structure hasa maximum seal strength in the range of about 10 N/25 mm to about 100N/25 mm, preferably in the range of about 15 N/25 mm to about 32 N/25mm, and more preferably about 20 N/25 mm to about 30 N/25 mm. In certainembodiments, the polyester-based film structure has a minimum sealstrength of greater than or equal to 10 N/25 mm, preferably greater thanor equal to 15 N/25 mm, and more preferably greater than or equal to 20N/25 mm. In certain embodiments, the minimum seal temperature to achievethe minimum seal strength is less than or equal to 115 degrees C.,preferably less than or equal to 100 degrees C., more preferably lessthan or equal to 90 degrees C. In certain embodiments, the minimum sealtemperature to achieve a seal strength of at least 10 N/25 mm is lessthan or equal to 115 degrees C., preferably less than or equal to 100degrees C., more preferably less than or equal to 90 degrees C.

The third ply 220 is interposed between the first ply 110 and the secondply 120. The third ply includes a polyester-based film 60, which isformed of a polyester-based polymeric composition. In certainembodiments, the polyester-based polymer composition comprises PBT, PET,or a blend of 0-100% by weight of PBT in PET, the ratio of which isadjustable depending on the packaging application. The film 60 can beclear polyester-based film. Alternatively, the film 60 can be white(e.g., via the additional of a pigment such as titanium dioxide) to addstiffness to the structure and improve the stain resistance propertiesafter the retort process. In certain embodiments, the third ply 220further includes a ceramic coating 20 formed on a first surface of thepolyester-based film 60. The ceramic coating 20 may be formed of amaterial as described above by way of reference to FIG. 5 . In certainpreferred embodiments, is formed of partially or fully oxidized silicon(SiO_(x), SiO₂), partially or fully oxidized aluminum (AlO_(x), Al₂O₃),or a mixture thereof. An additional polymer coating layer 25 suitablefor closing any cracks created during the retort process is disposed onthe ceramic coating layer 20.

In certain embodiments, the first ply 110 r has a thickness of 9 micronsto 100 microns. In certain embodiments, the second ply 120 has athickness of 9 microns to 100 microns. In certain embodiments, the thirdply 220 has a thickness of 9 microns to 100 microns. In certainpreferred embodiments, the gusseted portion of a polyester-based pouchis formed of a laminated film structure comprising the first ply 110 rand the second ply 120, where the total bending stiffness of thelaminated film structure of the gusseted portion is below or equal to0.05 N mm, and the front and back panels of the gusseted pouch areformed of a laminated film structure comprising the first ply 110, thethird ply 220, and the second ply 120.

Referring now to FIG. 8 , there appears a fourth embodiment packagingfilm structure 400, comprising a first ply 110, a third ply 220 f, and asecond ply, 120, which are laminated together. The first ply 110 is anouter ply, the second ply 120 is an inner ply, and the third ply 220 fis an intermediate ply interposed between the first and second plylayers. A first adhesive layer 40 a is interposed between the first ply110 and the third ply 220 f and a second adhesive layer 40 b isinterposed between the third ply 220 f and the second ply 120 f, to forma laminated structure. The adhesive layers 40 a and 40 b may be formedof an adhesive material as described above by way of reference to FIG. 5.

The first ply 110 is formed on an outer portion of the packaging filmstructure 400. The ply 110 includes polyester-based film 10, which maybe formed of PBT, PET, or a blend of 0-100% by weight of PBT in PET, asdescribed above by way of reference to FIG. 5 .

In certain embodiments, the first ply 110 further includes a ceramiccoating 20 formed on a first surface of the polyester-based ply 10. Theceramic coating 20 may be formed of a material as described above by wayof reference to FIG. 5 . In certain preferred embodiments, the ceramiccoating is formed of partially or fully oxidized silicon (SiO_(x),SiO₂), partially or fully oxidized aluminum (AlO_(x), Al₂O₃), or amixture thereof. An additional polymer coating layer 25 suitable forclosing any cracks created during the retort process is disposed on theceramic coating layer 20.

The second ply 120 includes a sealable polyester-based film 50. Incertain embodiments, the sealable polyester-based film 50 is formed of apolyester polymer 12 and a sealable polyester layer 55, such as isdescribed below by way of reference to FIG. 15 . In certain embodiments,the sealable polyester film 50 includes a barrier coating 20 and a topcoating 25, such as is described below by way of reference to FIG. 14 .In certain embodiments, the sealable polyester-based film 50 comprises apolyester-based layer 12 and a thin, amorphous, sealable polyester layer55. The sealable polyester-based film 50 defines a sealant layer and maycomprise any polyester-based polymer suitable for providing a hermeticseal in a finished packaging article, and preferably has a low sealinitiation temperature/melting point. In certain preferred embodiments,the sealable polyester layer 55 is an amorphous layer having a thicknessbetween 2 to 25 microns. The film 50 can be clear polyester sealablefilm. Alternatively, the film 50 can be white (e.g., via the additionalof a pigment such as titanium dioxide) to add stiffness to the structureand improve the stain resistance properties after the retort process. Incertain embodiments, the second ply 120 has static and kineticcoefficients of friction in the range of from about 0.1 to 0.4. Incertain embodiments, the seal initiation temperature is lower than 120°C. at 40 psi, 0.5 second dwell time. In certain embodiments, the sealinitiation temperature is lower than 100° C. at 40 psi, 0.5 second dwelltime. In certain embodiments, the ply 120 is selected of a materialwhich provides a seal strength of between about 10 N/25 mm to about 100N/25 mm, preferably about 15 N/25 mm to about 100 N/25 mm, and morepreferably about 20 N/25 mm to about 100 N/25 mm, in order for apackaging article to pass the retort process. In certain embodiments,the polyester-based film structure has a maximum seal strength in therange of about 10 N/25 mm to about 100 N/25 mm, preferably in the rangeof about 15 N/25 mm to about 32 N/25 mm, and more preferably about 20N/25 mm to about 30 N/25 mm. In certain embodiments, the polyester-basedfilm structure has a minimum seal strength of greater than or equal to10 N/25 mm, preferably greater than or equal to 15 N/25 mm, and morepreferably greater than or equal to 20 N/25 mm. In certain embodiments,the minimum seal temperature to achieve the minimum seal strength isless than or equal to 115 degrees C., preferably less than or equal to100 degrees C., more preferably less than or equal to 90 degrees C. Incertain embodiments, the minimum seal temperature to achieve a sealstrength of at least 10 N/25 mm is less than or equal to 115 degrees C.,preferably less than or equal to 100 degrees C., more preferably lessthan or equal to 90 degrees C.

The third ply 220 f is interposed between the first ply 110 and thesecond ply 120. The third ply includes a polyester-based film 60, whichis formed of a polyester-based polymeric composition. In certainembodiments, the polyester-based polymer composition comprises PBT, PET,or a blend of 0-100% by weight of PBT in PET, the ratio of which isadjustable depending on the packaging application. The film 60 can beclear polyester-based film. Alternatively, the film 60 can be white(e.g., via the additional of a pigment such as titanium dioxide) to addstiffness to the structure and improve the stain resistance propertiesafter the retort process. In certain embodiments, the third ply 220 ffurther includes a ceramic coating 20 formed on a first surface of thepolyester-based film 60. The ceramic coating 20 may be formed of amaterial as described above by way of reference to FIG. 5 . In certainpreferred embodiments, is formed of partially or fully oxidized silicon(SiO_(x), SiO₂), partially or fully oxidized aluminum (AlO_(x), Al₂O₃),or a mixture thereof. An additional polymer coating layer 25 suitablefor closing any cracks created during the retort process is disposed onthe ceramic coating layer 20.

A printing ink layer 30 f is disposed on an outward facing surface ofthe polyester-based film 60. The printing ink layer 30 f providesprinted indicia intended to appear on a packaging article formed fromthe film structure 400. Because the printing ink layer 30 f is appliedto the outward facing surface of the polyester-based film 60, theprinted material is effected in a front printed format. The printing inklayer 30 f can be applied to the outward facing surface of thepolyester-based film via any conventional printing method as would beunderstood by persons skilled in the art, including without limitation,using a rotogravure printing apparatus or flexographic printingapparatus.

In certain embodiments, the first ply 110 has a thickness of 9 micronsto 100 microns. In certain embodiments, the second ply 120 has athickness of 9 microns to 100 microns. In certain embodiments, the thirdply 220 f has a thickness of 9 microns to 100 microns. In certainpreferred embodiments, the gusseted portion of a polyester-based pouchis formed of a laminated film structure comprising the first ply 110 andthe second ply 120, where the total bending stiffness of the laminatedfilm structure of the gusseted portion is below or equal to 0.05 N mm,and the front and back panels of the gusseted pouch are formed of alaminated film structure comprising the first ply 110, the third ply 220f, and the second ply 120.

Referring now to FIG. 9 , there appears a fifth embodiment packagingfilm structure 500, comprising a first ply 110, a third ply 220 r, and asecond ply, 120, which are laminated together. The first ply 110 is anouter ply, the second ply 120 is an inner ply, and the third ply 220 ris an intermediate ply interposed between the first and second plylayers. A first adhesive layer 40 a is interposed between the first ply110 and the third ply 220 r and a second adhesive layer 40 b isinterposed between the third ply 220 r and the second ply 120, to form alaminated structure. The adhesive layers 40 a and 40 b may be formed ofan adhesive material as described above by way of reference to FIG. 5 .

The first ply 110 is formed on an outer portion of the packaging filmstructure 500. The ply 110 includes polyester-based film 10, which maybe formed of PBT, PET, or a blend of 0-100% by weight of PBT in PET, asdescribed above by way of reference to FIG. 5 .

In certain embodiments, the first ply 110 further includes a ceramiccoating 20 formed on a first surface of the polyester-based film 10. Theceramic coating 20 may be formed of a material as described above by wayof reference to FIG. 5 . In certain preferred embodiments, the ceramiccoating is formed of partially or fully oxidized silicon (SiO_(x),SiO₂), partially or fully oxidized aluminum (AlO_(x), Al₂O₃), or amixture thereof. An additional polymer coating layer 25 suitable forclosing any cracks created during the retort process is disposed on theceramic coating layer 20.

The second ply 120 includes a sealable polyester-based film 50. Incertain embodiments, the sealable polyester-based film 50 is formed of apolyester polymer 12 and a sealable polyester layer 55, such as isdescribed below by way of reference to FIG. 15 . In certain embodiments,the sealable polyester film 50 includes a barrier coating 20 and a topcoating 25, such as is described below by way of reference to FIG. 14 .In certain embodiments, the sealable polyester-based film 50 comprises apolyester-based layer 12 and a thin, amorphous, sealable polyester layer55. The sealable polyester-based film 50 defines a sealant layer and maycomprise any polyester-based polymer suitable for providing a hermeticseal in a finished packaging article, and preferably has a low sealinitiation temperature/melting point. In certain preferred embodiments,the sealable polyester layer 55 is an amorphous layer having a thicknessbetween 2 to 25 microns. The film 50 can be clear polyester sealablefilm. Alternatively, the film 50 can be white (e.g., via the additionalof a pigment such as titanium dioxide) to add stiffness to the structureand improve the stain resistance properties after the retort process. Incertain embodiments, the second ply 120 has static and kineticcoefficients of friction in the range of from about 0.1 to 0.4. Incertain embodiments, the seal initiation temperature is lower than 120°C. at 40 psi, 0.5 second dwell time. In certain embodiments, the sealinitiation temperature is lower than 100° C. at 40 psi, 0.5 second dwelltime. In certain embodiments, the ply 120 is selected of a materialwhich provides a seal strength of between about 10 N/25 mm to about 100N/25 mm, preferably about 15 N/25 mm to about 100 N/25 mm, and morepreferably about 20 N/25 mm to about 100 N/25 mm, in order for apackaging article to pass the retort process. In certain embodiments,the polyester-based film structure has a maximum seal strength in therange of about 10 N/25 mm to about 100 N/25 mm, preferably in the rangeof about 15 N/25 mm to about 32 N/25 mm, and more preferably about 20N/25 mm to about 30 N/25 mm. In certain embodiments, the polyester-basedfilm structure has a minimum seal strength of greater than or equal to10 N/25 mm, preferably greater than or equal to 15 N/25 mm, and morepreferably greater than or equal to 20 N/25 mm. In certain embodiments,the minimum seal temperature to achieve the minimum seal strength isless than or equal to 115 degrees C., preferably less than or equal to100 degrees C., more preferably less than or equal to 90 degrees C. Incertain embodiments, the minimum seal temperature to achieve a sealstrength of at least 10 N/25 mm is less than or equal to 115 degrees C.,preferably less than or equal to 100 degrees C., more preferably lessthan or equal to 90 degrees C.

The third ply 220 r is interposed between the first ply 110 and thesecond ply 120. The third ply includes a polyester-based film 60, whichis formed of a polyester-based polymeric composition. In certainembodiments, the polyester-based polymer composition comprises PBT, PET,or a blend of 0-100% by weight of PBT in PET, the ratio of which isadjustable depending on the packaging application. The film 60 can beclear polyester-based film. Alternatively, the film 60 can be white(e.g., via the additional of a pigment such as titanium dioxide) to addstiffness to the structure and improve the stain resistance propertiesafter the retort process. In certain embodiments, the third ply 220further includes a ceramic coating 20 formed on a first surface of thepolyester-based film 60. The ceramic coating 20 may be formed of amaterial as described above by way of reference to FIG. 5 . In certainpreferred embodiments, is formed of partially or fully oxidized silicon(SiO_(x), SiO₂), partially or fully oxidized aluminum (AlO_(x), A₂O₃),or a mixture thereof. An additional polymer coating layer 25 suitablefor closing any cracks created during the retort process is disposed onthe ceramic coating layer 20.

A printing ink layer 30 r is disposed on the inward facing surface ofpolyester-based film 60. In certain embodiments where thepolyester-based film 60 is a barrier polyester-based film, the printingink layer 30 r is disposed on the coating layer 25 on the surfaceopposite the surface facing the ceramic coating layer 20. The printingink layer 30 r provides printed indicia intended to appear on apackaging article formed from the film structure 500. Because theprinting ink layer 30 r is applied to the inward facing surface of thepolyester-based film 60, the printed material is effected in a reverseprinted format. The printing ink layer 30 r can be applied to the inwardsurface of the coating layer 25 via any conventional printing method aswould be understood by persons skilled in the art, including withoutlimitation, using a rotogravure printing apparatus or flexographicprinting apparatus.

In certain embodiments, the first ply 110 has a thickness of 9 micronsto 100 microns. In certain embodiments, the second ply 120 has athickness of 9 microns to 100 microns. In certain embodiments, the thirdply 220 r has a thickness of 9 microns to 100 microns. In certainpreferred embodiments, the gusseted portion of a polyester-based pouchis formed of a laminated film structure comprising the first ply 110 andthe second ply 120, where the total bending stiffness of the laminatedfilm structure of the gusseted portion is below or equal to 0.05 N mm,and the front and back panels of the gusseted pouch are formed of alaminated film structure comprising the first ply 110, the third ply 220r, and the second ply 120.

Referring now to FIG. 10 , there appears a sixth embodiment packagingfilm structure 600, comprising a first ply 110, a third ply 220, and asecond ply, 120 f, which are laminated together. The first ply 110 is anouter ply, the second ply 120 f is an inner ply, and the third ply 220is an intermediate ply interposed between the first and second plylayers. A first adhesive layer 40 a is interposed between the first ply110 and the third ply 220 and a second adhesive layer 40 b is interposedbetween the third ply 220 and the second ply 120 f, to form a laminatedstructure. The adhesive layers 40 a and 40 b may be formed of anadhesive material as described above by way of reference to FIG. 5 .

The first ply 110 is formed on an outer portion of the packaging filmstructure 600. The ply 110 includes polyester-based film 10, which maybe formed of PBT, PET, or a blend of 0-100% by weight of PBT in PET, asdescribed above by way of reference to FIG. 5 .

In certain embodiments, the first ply 110 further includes a ceramiccoating 20 formed on a first surface of the polyester-based film 10. Theceramic coating 20 may be formed of a material as described above by wayof reference to FIG. 5 . In certain preferred embodiments, the ceramiccoating is formed of partially or fully oxidized silicon (SiO_(x),SiO₂), partially or fully oxidized aluminum (AlO_(x), Al₂O₃), or amixture thereof. An additional polymer coating layer 25 suitable forclosing any cracks created during the retort process is disposed on theceramic coating layer 20.

The second ply 120 f includes a sealable polyester-based film 50. Incertain embodiments, the sealable polyester-based film 50 is formed of apolyester polymer 12 and a sealable polyester layer 55, such as isdescribed below by way of reference to FIG. 15 . In certain embodiments,the sealable polyester film 50 includes a barrier coating 20 and a topcoating 25, such as is described below by way of reference to FIG. 14 .In certain embodiments, the sealable polyester-based film 50 comprises apolyester-based layer 12 and a thin, amorphous, sealable polyester layer55. The sealable polyester-based film 50 defines a sealant layer and maycomprise any polyester-based polymer suitable for providing a hermeticseal in a finished packaging article, and preferably has a low sealinitiation temperature/melting point. In certain preferred embodiments,the sealable polyester layer 55 is an amorphous layer having a thicknessbetween 2 to 25 microns. The film 50 can be clear polyester sealablefilm. Alternatively, the film 50 can be white (e.g., via the additionalof a pigment such as titanium dioxide) to add stiffness to the structureand improve the stain resistance properties after the retort process. Incertain embodiments, the second ply 120 has static and kineticcoefficients of friction in the range of from about 0.1 to 0.4. Incertain embodiments, the seal initiation temperature is lower than 120°C. at 40 psi, 0.5 second dwell time. In certain embodiments, the sealinitiation temperature is lower than 100° C. at 40 psi, 0.5 second dwelltime. In certain embodiments, the ply 120 f is selected of a materialwhich provides a seal strength of between about 10 N/25 mm to about 100N/25 mm, preferably about 15 N/25 mm to about 100 N/25 mm, and morepreferably about 20 N/25 mm to about 100 N/25 mm, in order for apackaging article to pass the retort process. In certain embodiments,the polyester-based film structure has a maximum seal strength in therange of about 10 N/25 mm to about 100 N/25 mm, preferably in the rangeof about 15 N/25 mm to about 32 N/25 mm, and more preferably about 20N/25 mm to about 30 N/25 mm. In certain embodiments, the polyester-basedfilm structure has a minimum seal strength of greater than or equal to10 N/25 mm, preferably greater than or equal to 15 N/25 mm, and morepreferably greater than or equal to 20 N/25 mm. In certain embodiments,the minimum seal temperature to achieve the minimum seal strength isless than or equal to 115 degrees C., preferably less than or equal to100 degrees C., more preferably less than or equal to 90 degrees C. Incertain embodiments, the minimum seal temperature to achieve a sealstrength of at least 10 N/25 mm is less than or equal to 115 degrees C.,preferably less than or equal to 100 degrees C., more preferably lessthan or equal to 90 degrees C.

A printing ink layer 30 f is disposed on an outward facing surface ofthe sealable polyester-based film 50. The printing ink layer 30 fprovides printed indicia intended to appear on a packaging articleformed from the film structure 600. Because the printing ink layer 30 fis applied to the outward facing surface of the sealable polyester-basedfilm 50, the printed material is effected in a front printed format. Theprinting ink layer 30 f can be applied to the outward facing surface ofthe sealable polyester-based film via any conventional printing methodas would be understood by persons skilled in the art, including withoutlimitation, using a rotogravure printing apparatus or flexographicprinting apparatus.

The third ply 220 is interposed between the first ply 110 and the secondply 120 f. The third ply includes a polyester-based film 60, which isformed of a polyester-based polymeric composition. In certainembodiments, the polyester-based polymer composition comprises PBT, PET,or a blend of 0-100% by weight of PBT in PET, the ratio of which isadjustable depending on the packaging application. The film 60 can beclear polyester-based film. Alternatively, the film 60 can be white(e.g., via the additional of a pigment such as titanium dioxide) to addstiffness to the structure and improve the stain resistance propertiesafter the retort process. In certain embodiments, the third ply 220further includes a ceramic coating 20 formed on a first surface of thepolyester-based film 60. The ceramic coating 20 may be formed of amaterial as described above by way of reference to FIG. 5 . In certainpreferred embodiments, is formed of partially or fully oxidized silicon(SiO_(x), SiO₂), partially or fully oxidized aluminum (AlO_(x), Al₂O₃),or a mixture thereof. An additional polymer coating layer 25 suitablefor closing any cracks created during the retort process is disposed onthe ceramic coating layer 20.

In certain embodiments, the first ply 110 has a thickness of 9 micronsto 100 microns. In certain embodiments, the second ply 120 f has athickness of 9 microns to 100 microns. In certain embodiments, the thirdply 220 has a thickness of 9 microns to 100 microns. In certainpreferred embodiments, the gusseted portion of a polyester-based pouchis formed of a laminated film structure comprising the first ply 110 andthe second ply 120 f, where the total bending stiffness of the laminatedfilm structure of the gusseted portion is below or equal to 0.05 N mm,and the front and back panels of the gusseted pouch are formed of alaminated film structure comprising the first ply 110, the third ply220, and the second ply 120 f.

Referring now to FIG. 11 , there appears a seventh embodiment packagingfilm structure 700, comprising a first ply 110, a third ply 220, asecond ply 120, and one or more (up to “X”) plies, designated 220 a,where X is 1, 2, 3, 4, 5, 6, 7, 8, 9, or more, and N is 4, 5, 6, 7, 8,9, 10, 11, 12, or more, which are laminated together. The first ply 110is an outer ply, the second ply 120 is an inner ply, and the third ply220 is an intermediate ply. A first adhesive layer 40 a is interposedbetween the first ply 110 and the third ply 220 and a second adhesivelayer 40 b is interposed between the third ply 220 and the fourth ply220 a, and further adhesive layers 40 c are disposed between the fourthand subsequent plies 220 a and the second ply 120 f to form a laminatedstructure. The adhesive layers 40 a, 40 b, and 40 c may be formed of anadhesive material as described above by way of reference to FIG. 5 .

FIGS. 12 and 13 illustrate exemplary polyester-based films. FIG. 12illustrates a three-layer barrier-coated polyester-based film, which isoperable to embody the polyester-based film layers 10 and 60. Thethree-layer barrier-coated polyester-based film comprises apolyester-based polymer layer 12, a barrier coating layer 20, and apolymer top coating layer 25. In certain embodiments, the composition ofthe polyester-based polymer 12 comprises PBT, PET, or a blend of 0-100%by weight of PBT in PET, the ratio of which is adjustable depending onthe packaging application. In certain embodiments, the barrier coatinglayer 20 is a ceramic coating formed of partially or fully oxidizedaluminum or silicon or a blend of both. In certain preferredembodiments, the ceramic coating is formed of partially or fullyoxidized silicon (SiO_(x), SiO₂), partially or fully oxidized aluminum(AlO_(x), Al₂O₃), or a mixture thereof. FIG. 13 illustrates apolyester-based film structure comprising a polyester polymer layer 12,which is operable to embody the polyester-based films 10 and 60. Incertain embodiments, the composition of the polyester-based polymer 12comprises PBT, PET, or a blend of 0-100% by weight of PBT in PET, theratio of which is adjustable depending on the packaging application. Thefilm 60 can be clear polyester-based film. Alternatively, the film 60can be white (e.g., via the additional of a pigment such as titaniumdioxide) to add stiffness to the structure and improve the stainresistance properties after the retort process.

FIG. 14 illustrates an exemplary sealable polyester-based film, which isoperable to embody the sealable polyester-based film 50. The sealablepolyester-based film 50 may comprise a polyester-based polymer 12 (suchas described by way of reference above to FIG. 12 or 13 ) further havinga barrier layer 20 on a first surface of the polyester-based polymer 12,and a sealable polyester layer 55 on a second surface of thepolyester-based polymer 12. In certain embodiments, the barrier layer isa ceramic coating layer 20, wherein the ceramic coating is formed ofpartially or fully oxidized aluminum or silicon or a blend of both. Incertain embodiments, the ceramic coating 20 is formed of a partially orfully oxidized silicon (SiO_(x), SiO₂), partially or fully oxidizedaluminum (AlO_(x), Al₂O₃), or a mixture thereof. A polymer top coating25 is further included on the surface of the barrier layer 20 oppositethe surface facing the polyester-based polymer 12. The top coating layer25 is disposed on the ceramic coating layer 20 and is suitable forclosing any cracks created during the retort process.

FIG. 15 illustrates an exemplary sealable polyester-based film, which isoperable to embody the sealable polyester-based film 50. The sealablepolyester-based film 50 may comprise a polyester-based polymer layer 12and a sealable polyester layer 55.

The present development was reduced to practice and the heat sealstrength, oxygen and water vapor permeability, dimensional stability,hermetic seal pressure, package pressure, gusset opening pressure,kinetic and static coefficients of friction of sealant layer werecompared to traditional PET film/foil/cast polypropylene (CPP) films(see Table 1).

TABLE 1 Control Recycle Ready Body: PET/foil/CPP Polyester Gusset: BasedPET/foil/BoN/CPP Gusseted Pouches CoF <0.4 <0.4 Heat Seal Strength >30N/25 mm >10 N/25 mm Leak test Pass Pass Filling with air under 0.1 barpressure for 1 hour Rhodamine solution for 1 hour Water vacuum testunder 18 in Hg for 1 min Pressure test Pass Pass Filling the sample withwater and apply 1 bar pressure for 4 hrs Gusset opening  40 mbar  <30mbar Burst test 800 mbar <500 mbar Fill with air till pouch breaksLinear tear test Pass Pass Internal flex crack testing Pass Pass(Qualitatively) OTR (cc/100 in²/day) <0.01 <0.05 (23° C., 0% RH) Beforeand after retort test process WVTR (g/100 in²/day) <0.01 <0.05 (38° C.,90% RH) Before and after retort test process Retort Test Pass Pass up to130° C., counter pressure involved Dimensional Stability after <2.5%<2.5% retort (MD/TD %) Migration testing for retort Pass Pass condition130° C., 90 min

As can be seen from Table 1, the heat seal strength is within the rangeof 15-100 N/25 mm required to pass the retort process, while creating agood ultrasonic seal. The oxygen and water vapor permeability valuesafter retort processing are within the ranges to ensure that productquality and shelf life are not compromised. The dimensional stability iswithin the 3% maximum threshold required to ensure that a pouch formedof the film structure will have good dimensional stability and maintainthe look of the pouch. The gusset opening pressure is within the 40 mBarmaximum threshold for running on pouch filling equipment with no issues.The coefficients of kinetic and static friction are within a rangesuitable for running on pouch forming and filling equipment with noissues.

Referring now to FIG. 16 , there appears a graph of seal strength as afunction of temperature comparing a gusseted standup pouches formed ofpolyester film using a polyester sealant layer having a low sealinitiation temperature in accordance with the present invention(referred to herein as “suitable sealant”) to three differentcommercially available polyester sealant layers conventionally used fornon-gusseted polyester film packaging, but which have been found to beunsuitable for use with gusseted pouch constructions (referred to hereinas “non-suitable sealants”). The tests were conducted at a sealingpressure of 40 psi and a dwell time of 0.5 seconds.

As clearly seen in FIG. 16 , the seal initiation temperature of thesuitable sealant herein has a seal initiation of less than 100 degreesC.; whereas, the seal initiation temperature of the non-suitablesealants all above 110 degrees C. As can also be seen in FIG. 16 , thesealant achieved seal strengths, e.g., in the range of 14-20 N/25 mm, atlower temperatures, e.g., in the range of about 90 to 110 degrees C.,which were below the seal initiation temperatures of the unsuitablesealants. In addition, as shown in FIG. 16 , at higher temperatures, thesuitable sealant resulted in significantly higher seal strengths thanwas achievable with the unsuitable sealants.

In preparing gusseted pouches in accordance with this disclosure, thefilms using the unsuitable sealant layers were found not to work forgusseted pouch applications in they achieved a sealing strength of only10 N/25 mm at a sealing temperature of around 120-130 degrees C. andnone of them achieved maximum seal strength. In contrast, the pouchesemploying the suitable sealant layer in accordance with this disclosureachieved a minimum seal strength of 10 N/25 mm at relatively low sealingtemperatures, e.g., approximately 90 degrees C., and can reach a maximumseal strength when the sealing temperature is greater than or equal to110 degrees C., wherein the maximum sealing strength is between 20 and32 N/25 mm, including 20 N/25 mm, 30 N/25 mm, and 32 N/25 mm.

Referring now to FIGS. 17A and 17B, there appears an exemplary gussetedpouch constructed with polyester film having a suitable polyestersealant in accordance with this disclosure. An iodopovidone solution wasused to detect leaks at the triple point regions 1020 a. As can be seenin FIGS. 17A and 17B, the pouch achieved a hermetic seal at the triplepoint regions 1020 a. FIGS. 18A and 18B are images of a gusseted pouchconstructed with polyester film having a conventional, unsuitablesuitable polyester sealant. An iodopovidone solution was used to detectleaks at the triple point regions 1020 b. As can be seen in FIGS. 18Aand 18B, the pouch using the conventional, unsuitable suitable polyestersealant did not achieve a hermetic seal at the triple point regions 1020b.

In comparing pillow shaped bags having a longitudinal fin seal, of thetype disclosed in U.S. Pat. No. 6,543,208, it was found that a hermeticseal was provided at the apices (i.e., junctions between thelongitudinal seal and the transverse end seals) even when using theconventional amorphous polyester sealant layers that are non-suitablefor gusseted pouches, even with relatively thick and/or stiff films.Thus, it has been found that it is much easier to provide a hermeticseal at the apex of a conventional pillow shaped bag with fin seal thanfor the triple point in a gusseted stand-up pouch due to the extra filmlayer resulting from the presence of the bottom gusset panel.

The invention has been described with reference to the preferredembodiment. Modifications and alterations will occur to others upon areading and understanding of the preceding detailed description. It isintended that the invention be construed as including all suchmodifications and alterations insofar as they come within the scope ofthe appended claims or the equivalents thereof

1-27. (canceled)
 28. A polyester-based film comprising: a first plycomprising: a first layer formed of a first polyester-based polymericcomposition, wherein the first polyester-based polymeric compositioncomprises polybutylene terephthalate, polyethylene terephthalate, or ablend thereof, the first layer having a first surface and a secondsurface opposite the first surface; and a second ply comprising: asecond layer, the second layer having a first surface and a secondsurface opposite the first surface, and wherein the second layer isformed of a sealable polyester; and a third layer formed of a secondpolyester-based polymeric composition, wherein the secondpolyester-based polymeric composition comprises polybutyleneterephthalate, polyethylene terephthalate, or a blend thereof; and anadhesive layer interposed between the first ply and the second ply, theadhesive layer laminating the first ply to the second ply, wherein thefirst surface of the third layer faces the second surface of the firstlayer.
 29. The polyester-based film of claim 28, wherein thepolyester-based film has a thickness in the range of about 9 microns to100 microns.
 30. The polyester-based film of claim 28, wherein thesecond layer has a thickness in the range of about 2 microns to 25microns.
 31. The polyester-based film of claim 28, further comprising aprinted layer disposed intermediate the first layer and the adhesivelayer.
 32. The polyester-based film of claim 28, wherein the first plyfurther comprises: a fourth layer formed of a ceramic coating, thefourth layer having a first surface and a second surface opposite thefirst surface, wherein the first surface of the fourth layer faces thesecond surface of the first layer; and a fifth layer, the fifth layerinterposed between the fourth layer and the adhesive layer.
 33. Thepolyester-based film of claim 28, wherein the second ply furthercomprises: a fourth layer formed of a ceramic coating, the fourth layerhaving a first surface and a second surface opposite the first surface,wherein the second surface of the fourth layer faces the first surfaceof the third layer; and a fifth layer, the fifth layer interposedbetween the fourth layer and the adhesive layer.
 34. The polyester-basedfilm of claim 28, wherein the polyester-based film has a seal initiationtemperature of between 85° C. and 120° C.
 35. The polyester-based filmof claim 28, wherein the polyester-based film is configured to form aheat seal with itself, wherein the heat seal has a seal strength in therange of about 10 N/25 mm to about 100 N/25 mm when sealed at a sealingpressure of 40 psi, a dwell time of 0.5 second, and a sealingtemperature of 90-100 degrees C.
 36. The polyester-based film of claim28, wherein the polyester-based film is configured to form an ultrasonicseal with itself.
 37. The polyester-based film of claim 28, wherein thepolyester-based film is configured to form a heat seal with itself, andwherein the heat seal has a maximum seal strength in the range of about10 N/25 mm to about 100 N/25 mm.
 38. The polyester-based film of claim28, wherein the polyester-based film is configured to form a heat sealwith itself, and wherein the heat seal has a minimum seal strength inthe range of about 10 N/25 mm to about 15 N/25 mm.
 39. Thepolyester-based film of claim 38, wherein the minimum seal temperatureto achieve said minimum seal strength is in the range of from about 115degrees C. to about 90 degrees C.
 40. The polyester-based film of claim28, wherein the minimum seal temperature to achieve a seal strength ofat least 10 N/25 mm is in the range of from about less than or equal to115 degrees C. to about 90 degrees C.
 41. The polyester-based film ofclaim 28, wherein the sealable polyester layer has a static coefficientof friction in the range of about 0.1 to 0.4 and a kinetic coefficientof friction in the range of about 0.1 to 0.4.
 42. The polyester-basedfilm of claim 28, wherein: the polyester-based film has an oxygentransmission rate before undergoing a retort process in the range ofabout 0.1 cc/100 in²/day at 23 degrees C. and 0% relative humidity toabout 0.05 cc/100 in²/day at 23 degrees C. and 0% relative humidity; andthe polyester-based film has a moisture vapor transmission rate beforeundergoing a retort process in the range of about 0.1 g/100 in²/day at38 degrees C. and 90% relative humidity to about 0.05 g/100 in²/day at38 degrees C. and 90% relative humidity.
 43. The polyester-based film ofclaim 28, wherein: the polyester-based film has an oxygen transmissionrate after undergoing a retort process in the range of about 0.1 cc/100in²/day at 23 degrees C. and 0% relative humidity to about 0.05 cc/100in²/day at 23 degrees C. and 0% relative humidity; and thepolyester-based film has a moisture vapor transmission rate afterundergoing a retort process in the range of about 0.1 g/100 in²/day at38 degrees C. and 90% relative humidity to about 0.05 g/100 in²/day at38 degrees C. and 90% relative humidity.
 44. A polyester-based filmcomprising: a first ply comprising: a first layer formed of a firstpolyester-based polymeric composition, wherein the first polyester-basedpolymeric composition comprises polybutylene terephthalate, polyethyleneterephthalate, or a blend thereof, the first layer having a firstsurface and a second surface opposite the first surface; a second plycomprising: a second layer, the second layer having a first surface anda second surface opposite the first surface, and wherein the secondlayer is sealable polyester layer; and a third layer formed of a secondpolyester-based polymeric composition, wherein the secondpolyester-based polymeric composition comprises polybutyleneterephthalate, polyethylene terephthalate, or a blend thereof; a thirdply comprising: a fourth layer formed of a third polyester-basedpolymeric composition, the fourth layer having a first surface and asecond surface opposite the first surface; a first adhesive layerinterposed between the first ply and the third ply, the first adhesivelayer laminating the first ply to the third ply, wherein the firstsurface of the fourth layer faces the second surface of the first layer;and a second adhesive layer interposed between the second ply and thethird ply, the second adhesive layer laminating the second ply to thethird ply, wherein the second surface of the fourth layer faces thefirst surface of the third layer.
 45. The polyester-based film of claim44, wherein the third polyester-based polymeric composition comprisespolybutylene terephthalate, polyethylene terephthalate, or a blendthereof.
 46. The polyester-based film of claim 44, wherein thepolyester-based film further comprises at least one of: a first printedlayer disposed intermediate the first layer and the first adhesivelayer; a second printed layer disposed intermediate the fourth layer andthe first adhesive layer; a third printed layer disposed intermediatethe fourth layer and the second adhesive layer; and a fourth printedlayer disposed intermediate the third layer and the second adhesivelayer.
 47. The polyester-based film of claim 44, wherein each of thefirst ply, third ply, and the second ply have a thickness in the rangeof about 9 microns to 100 microns.
 48. The polyester-based film of claim44, wherein the sealable polyester layer has a thickness in the range ofabout 2 microns to 25 microns.
 49. The polyester-based film of claim 44,wherein the first ply further comprises: a fifth layer formed of aceramic coating, the fifth layer having a first surface and a secondsurface opposite the first surface, wherein the first surface of thefifth layer faces the second surface of the first layer; and a sixthlayer, the fifth layer interposed between the first layer and the firstadhesive layer.
 50. The polyester-based film of claim 44, wherein thesecond ply further comprises: a fifth layer formed of a ceramic coating,the fifth layer having a first surface and a second surface opposite thefirst surface, wherein the first surface of the fifth layer faces thesecond adhesive layer; and a sixth layer, the sixth layer interposedbetween the fifth layer and the second adhesive layer.
 51. Thepolyester-based film of claim 44, wherein the sealable polyester layerhas a static coefficient of friction in the range of about 0.1 to 0.4and a kinetic coefficient of friction in the range of about 0.1 to 0.4.